home   genetic news   bioinformatics   biotechnology   literature   journals   ethics   positions   events   sitemap
 
  HUM-MOLGEN -> Genetic News | search  
 

Perfect Fit For Immune Recognition

 
  November, 29 2005 11:31
your information resource in human molecular genetics
 
     
Mice lacking a particular enzyme exhibit abnormal immune responses, resulting from a less than perfect fit of protein bits displayed to immune cells, according to a paper in January's Nature Immunology.

Nilabh Shastri and colleagues show that mice lacking the enzyme ERAAP fail to cleave antigenic proteins properly. Their results suggest immune cell recognition of tumors or virally infected cells might depend on ERAAP activity.

The immune system is constantly on the lookout for sick cells. Immune cells distinguish healthy cells from infected or abnormal cells by the array of peptides (small bits of protein) displayed on their surface by specialized molecules known as major histocompatibility complex (MHC) proteins. First recognized as important for tissue matching in transplantation studies, MHC proteins present snapshots of the protein repertoire found inside the cell. This 'peptide presentation' involves coordinated cleavage of cellular proteins into peptides and loading of this peptide cargo into a groove found on the MHC molecule, whereupon peptide-MHC complexes travel to the cell surface where they are 'sampled' by the circulating immune cells.

ERAAP, which stands for "endoplasmic reticulum aminopeptidase associated with antigen processing", trims peptides in the ER and thereby allows peptides to 'fit' better in the MHC groove. Shastri and colleagues show loss of ERAAP decreases the stability of peptide-MHC interactions, which results in less MHC expressed on cell surfaces and those MHC molecules that do make it to the surface readily lose their peptide cargo or display altered peptide repertoires. ERAAP-deficient mice mount weaker immune responses to foreign antigens. ERAAP can thus be considered as a quality control enzyme required for proper immune cell recognition.

Author contact:

Nilabh Shastri (University of California Berkeley, CA, USA)
E-mail: nshastri@socrates.berkeley.edu

Abstract available online.

(C) Nature Immunology press release.


Message posted by: Trevor M. D'Souza

print this article mail this article
Latest News
Variants Associated with Pediatric Allergic Disorder

Mutations in PHF6 Found in T-Cell Leukemia

Genetic Risk Variant for Urinary Bladder Cancer

Antibody Has Therapeutic Effect on Mice with ALS

Regulating P53 Activity in Cancer Cells

Anti-RNA Therapy Counters Breast Cancer Spread

Mitochondrial DNA Diversity

The Power of RNA Sequencing

‘Pro-Ageing' Therapy for Cancer?

Niche Genetics Influence Leukaemia

Molecular Biology: Clinical Promise for RNA Interference

Chemoprevention Cocktail for Colon Cancer

more news ...

Generated by News Editor 2.0 by Kai Garlipp
WWW: Kai Garlipp, Frank S. Zollmann.
7.0 © 1995-2023 HUM-MOLGEN. All rights reserved. Liability, Copyright and Imprint.